noun
Refers specifically to a rocket-propelled munition or projectile, not a space launch vehicle.
敵はロケット弾で攻撃してきた。
The enemy attacked with rocket projectiles.
ロケット is a general term for a rocket (engine or vehicle), while ロケット弾 specifically means a rocket-propelled projectile or warhead.
Compound of ロケット (rocket) and 弾 (projectile, bullet).